Field of the Invention
The present disclosure relates to an image sensor, and in particular to an image sensor having grating structure on the filter unit.
Description of the Related Art
In general, a digital camera utilizes an image sensor to sense light and generate an image signal, and thus a picture taken by the digital camera can be generated according to the image signal.
As digital cameras continue to develop, high-quality image signals are increasingly required. The image sensors using a backside illumination (BSI) technology have light pipe structures to guide light to photodiodes. The image sensors have greater photosensitivity and image quality.
Although image sensors have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects. Consequently, it is desirable to provide a solution for improving image sensors.